In laser direct-write (LDW) techniques, a laser beam is used to create a patterned surface with spatially-resolved three-dimensional structures by controlled material ablation or deposition. Laser-induced forward transfer (LIFT) is an LDW technique that can be applied in depositing micro-patterns on a surface.
In LIFT, laser photons provide the driving force to catapult a small volume of material from a donor film toward an acceptor substrate. Typically, the laser beam interacts with the inner side of the donor film, which is coated onto a non-absorbing carrier substrate. The incident laser beam, in other words, propagates through the transparent carrier before the photons are absorbed by the inner surface of the film. Above a certain energy threshold, material is ejected from the donor film toward the surface of the substrate.
Some LIFT-based printing systems have been described in the patent literature. For example, U.S. Patent Application Publication 2005/0212888 describes a printing process for the transfer of a printing substance from an ink carrier to an imprinting material with the help of an energy-emitting apparatus, such as a laser, which emits electromagnetic waves.
LIFT processes may be used to transfer various materials from a donor to a receiving substrate. For example, U.S. Patent Application Publication 2009/0074987 describes the use of laser decal transfer to generate thin film features by directing laser pulses of very low energy to illuminate an area of a thin layer of a high-viscosity rheological fluid. The decal transfer process is said to allow for the release and transfer to the receiving substrate of a uniform and continuous layer identical in shape and size to the laser-irradiated area of the target substrate. The released layer is transferred with almost no change to its initial size and shape.